1. Field of the Invention
The present invention relates to a power tool such as a nailing machine, and more particularly, to a combustion power tool that performs a predetermined processing work by utilizing a high pressure impact force generated upon explosive combustion of flammable gas.
2. Description of the Related Art
Japanese Patent Publication Nos. 1-34753 (D1) and 5-55278 (D2) disclose an example of a combustion power tool. The known power tool is powered by a piston/cylinder-type internal combustion engine. In the reference D1, a fan is disposed within a combustion chamber where a combustion gas is burned. The fan serves to facilitate mixture of fuel and air and diffusion of the mixture within the combustion chamber, thereby expediting combustion. On the other hand, in the reference D2, a plurality of combustion chambers are provided and divided by partitions that have lattice-like communication holes. Each of the combustion chambers has a fuel injection hole, such that fuel and air can be efficiently mixed in each of the combustion chambers and the mixture can be efficiently diffused within the combustion chamber.
According to the reference D1, because the rotary fan is disposed within the combustion chamber, the mechanism of the power tool is complicated. According to the reference D2, although a technique for efficiently generating and diffusing the mixture within each of the combustion chambers is disclosed, further improvements are desired in order to improve the combustion efficiency of the mixture and to simplify the exhaust system for the combustion gas.